The present invention relates to an oil filter for use in an internal combustion engine for removing foreign matters contained in lubricating oil, particularly of the kind having a filter element that can be removed from a housing and replaced as a unit for maintaining the oil filter against clogging or the like.
An oil filter of this kind is disclosed in Japanese Unexamined Patent Publication No. 10-146503.
The oil filter includes a filter housing consisting of a housing main body having an oil inlet passage and an oil outlet passage and a cover detachably attached to an opening portion of the housing main body. At an oil flowing space within the filter housing is disposed a filter element. At the time of replacement of the filter element in such an oil filter, the cover is first removed from the housing main body, then the oil remaining within the housing main body is drained or discarded and thereafter the filter element is removed from the filter main body.